1. Field of the Disclosure
This disclosure generally relates to a human machine interface device and, more particularly, to an optical object tracking device and operating method thereof that may remove the moving background noise.
2. Description of the Related Art
The conventional optical object tracking device generally includes a light source, an image sensor and a processing unit, wherein the light source is configured to illuminate an approaching object; the image sensor is configured to capture a plurality of image frames containing the object; and the processing unit is configured to track the motion of the object according to the image frames.
However, besides the object image, the image frames captured by the image sensor may further include the ambient light image. Conventionally, in order to remove the ambient light image, the image sensor is arranged to capture bright image frames corresponding to the turning on of the light source and dark image frames corresponding to the turning off of the light source. Then, the processing unit calculates the differential image of the bright image frames and the dark image frames so as to eliminate the ambient light image. Although this denoising method can eliminate the noise caused by a fixed ambient light source, when the position of the ambient light source changes with time, the background noise can not be effectively eliminated only by calculating the differential image between the bright image frames and the dark image frames. Accordingly, the processing unit is not able to correctly track the motion of the object according to the differential image.
Accordingly, the present disclosure further provides an object tracking device and an operating method thereof that may effectively eliminate the noise caused by the moving background.